Device for promoting the growth of plants

ABSTRACT

Devices and methods for promoting the growth of plants, which transport the plants using a conveyor belt where roots of the plants protrude into a region located below a lower surface of the conveyor belt and at least parts of leaves and/or fruits of the plants protrude into a region located above an upper surface of the conveyor belt which opposes the lower surface. The conveyor path moves along a closed circular or oval path such that a deflection occurs in the region of an upper deflection point and in the region of a lower deflection point, which interconnect vertical sections.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation in part of U.S. patent application Ser. No.16/618,084, filed Nov. 27, 2019, which is a a US national phaseapplication under 35 USC § 371 of international patent application no.PCT/EP2018/064182, filed May 30, 2018, which itself claims priority toEuropean application 17173370.2, filed May 30, 2017. Each applicationreferred to in this paragraph is herein incorporated by reference in itsentirety.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a device for automated plant cultivation andmore specifically to a device having a conveyor belt that can be movedalong a conveyor path for transporting plants. While the plants arebeing transported along the conveyor path, which extends at leastapproximately horizontally in at least one first section and at leastapproximately vertically in at least one second section, the plants areat least temporarily supplied with water and nutrients by a nutrientsupply unit.

BACKGROUND OF THE INVENTION

Hydroponic and aeroponic plant cultivation has been known for manyyears; in particular in the last decades, these plant-cultivatingmethods have been used for intensively exploiting cultivation systems,particularly for greenhouse crops, e.g. tomatoes, cucumbers andlettuces. The mass production of agricultural products in fullyair-conditioned buildings in which external influences are strictlycontrolled is also referred to as “indoor farming.”

In this connection, there are known systems for cultivating plants inwhich the plants are arranged in a shelf system and supplied with anutrient medium in an automated manner during the growth phase. Onesystem of this kind is described in JP 2014-168420 A, for example. Inthis case, the plants intended to be cultivated are individually fixedin a carrier medium in a horizontal plane and are supplied with waterand nutrients by means of regular nutrient medium flooding and drainage.In addition, the plants are artificially illuminated by fluorescenttubes or LEDs attached directly above the plants.

Furthermore, AT 250728 discloses a special greenhouse in the form of atower greenhouse. What is essential in this case is that the height of abuilding is exploited to implement a conveyor path for cultivatingplants. The described greenhouse has a plurality of plant-transportingconveyor belts arranged in a serpentine manner; the conveyor belt is inthe form of a circulating path and has upper and lower deflectionpulleys such that the plants can be moved vertically in differentdirections. To ensure efficient illumination, suitable fluorescent tubesare provided between the vertically arranged conveyor belts.

A further technical solution for automated plant cultivation isdescribed in US 2012/0279122 A1. The described system has a conveyorbelt that is arranged in a serpentine manner and extends vertically inpart. To deflect the conveyor belt, corresponding deflection pulleys areprovided. Furthermore, special containers are provided to transport theplants; carrier material for holding seeds or plants is located in saidcontainers, which are hooked into the circulating conveyor belt by meansof special hook elements. In this case, the described containers forholding the plants extend over the entire range of the conveyor belt andcan each hold a plurality of plants one next to the other.

Despite the increased energy demand, the known automated systems forcultivating plants have a number of advantages over conventionalagriculture in fields. In addition to complete weather independence, theclimatic conditions inside the greenhouse can be optimally adapted toany given plants, thereby achieving constant plant growth. Furthermore,owing to special water recovery systems, a significantly smaller amountof water is required to cultivate the plants than if farming fieldsoutdoors. Moreover, a comparably small amount of fertilizer is required,and cultivating plants in fully air-conditioned spaces makes it possibleto grow the plants without pesticides.

Furthermore, the use of vertically arranged conveyor paths achieves theadvantage of significantly improved exploitation of the availablesurface area. This is highly advantageous in particular in urban areasand developed countries that have a comparably small amount of surfacearea suitable for agriculture, such as Japan.

The problem with the known systems for automated plant cultivation infully air-conditioned rooms is often that it is relatively complex toadapt the used systems to different plants. When the plants grown arechanged, account has to be taken of the fact that the size of differentplants changes to different extents and in different periods of time inthe growth phase. It is difficult to adapt the known systems forautomated plant cultivation to any given altered conditions. What ismore, supplying the plants with the required nutrients and water withoutcausing damage to the leaves or roots often presents problems.

SUMMARY OF THE INVENTION

Proceeding from the known prior-art systems for automated plantcultivation and the above-mentioned problems, the problem addressed bythe invention is that of providing a plant cultivation system thatallows crops and ornamental plants to be cultivated, preferably inclosed spaces, in a manner that is simple and adapted to the plantgrowth phase. The specified technical solution is intended to allow thecultivation of plants to be practically entirely automated, inparticular in a comparably simple manner, from placing a seed toharvesting the fully matured plant. Furthermore, it is intended to beensured that the water and nutrient requirements can be kept to aminimum. The device according to the invention is characterized by asimple structural design that preferably can be achieved using the knownsystem components for constructing automated greenhouse systems.

The aforementioned problem is solved by a device for promoting thegrowth of plants, in particular for automated plant cultivation, thedevice having a conveyor belt that can be moved along a conveyor pathand is intended for transporting plants at least in sections. Thetransported plants, while being moved along the conveyor path, are atleast temporarily illuminated and supplied with nutrients and water by anutrient supply and, while being conveyed along the conveyor path, aremoved at least approximately horizontally in at least one first sectionand at least approximately vertically in at least one second section.

The plants are at least temporarily fixed relative to the conveyor beltduring transport along the conveyor path such that at least parts ofroots of the plants protrude into a region located below a lower surfaceof the conveyor belt, while at least parts of leaves and/or fruits ofthe plants protrude into a region located above an upper surface of theconveyor belt which opposes the lower surface, a nutrient-medium supplybeing arranged below the conveyor belt such that the plants fixed on theconveyor belt, in particular the roots below the conveyor belt, areaeroponically supplied with nutrient medium. In this context, essentialfeatures of the invention are that the plants, during their growthphase, are fixed on the conveyor belt, continuously moved and at leasttemporarily transported along a light source, and that a nutrient-mediumsupply, in particular having spray nozzles, is located spaced apart fromthe lower surface of the conveyor belt, the nutrient-medium supplyensuring that the plants are aeroponically supplied with nutrient mediumin said region. Furthermore, during the movement, which is preferablyboth vertical and at least temporarily horizontal, the root region iscontinuously supplied with nutrients. On account of the specialarrangement of the conveyor path having at least approximatelyvertically upwardly and downwardly extending path sections, the plantsare continuously orbitropically realigned, which encourages plantgrowth.

In a specific embodiment of the invention, the conveyor belt includes,at least in regions, a carrier material in which the plants are at leasttemporarily fixed during transport along the conveyor path. Preferably,the carrier material is selected such that the seeds or plants are heldfirmly in place and the material can also distribute and at leasttemporarily store water and/or nutrient medium. Since the deviceaccording to the invention transports the plants at least temporarilyapproximately vertically, it is possible, according to a particulardevelopment of the invention, for the plants to be continuously moved,during the growth phase thereof, along an illumination source and/ortowards said illumination source, the plants preferably beingilluminated as soon as they are moved vertically. Advantageously, theroot region located on the lower surface of the conveyor belt issimultaneously aeroponically supplied with nutrients and moisture. Theaeroponic supply of nutrients to the root region also preferably takesplace at least temporarily while the plants are being moved vertically.In this connection, it is conceivable for an upper deflection point tobe provided between two vertically extending sections of the conveyorpath such that the plants, together with the conveyor belt, are movedvertically upwards and then vertically downwards after passing thedeflection point, the orientation of the plants, from the root to thetip of the shoot, being perpendicular to said movement direction.

It is generally conceivable to use natural light and/or artificial lightfor illumination, said artificial light being generated by means of anillumination unit having, for example, at least one fluorescent tubeand/or LED. The provision of an illumination unit for generating lightis advantageous in that the plants can be illuminated in a selectivemanner, in particular in a manner adapted to the type of plant to begrown and/or aligned with the plant growth, and at all times ifrequired. According to a particular development of the invention, theplants are only illuminated in particular regions of the conveyor path,in particular in selected regions in which the plants are movedvertically and particularly preferably over half of the total verticalregions such that a day/night rhythm can be imitated. Advantageously,the plants are illuminated by vertically arranged LED panels or otherillumination systems.

According to a specific development, the illumination unit is designedsuch that the plants are illuminated in specially selected sections ofthe conveyor path. Advantageously, the plants are illuminated while theyare being moved continuously upwards along a vertical section of theconveyor path. Moreover, it is advantageous for the plants to be atleast temporarily no longer illuminated after passing the deflectionpoint, in particular as soon as said plants are being moved verticallydownwards.

In a particularly advantageous embodiment, the plants fixed on theconveyor belt, in particular the roots below the conveyor belt, areaeroponically supplied with nutrient medium as soon as said plants arebeing moved vertically, while the plants are moved at least in partthrough an immersion bath in the region of a lower deflection point,which is located between two vertically extending sections of theconveyor path, such that the plants, in particular the roots, arehydroponically supplied with nutrients in said region. Over theserpentine or meandering conveyor path having vertically extending pathsections, between which lower and upper deflection points or regions arelocated, the plants are thus continuously supplied with nutrients andmoisture. A nutrient-medium misting system is preferably used toaeroponically water the roots of the plants. By means of an automatedplant cultivation system designed as described above, it is preferablypossible for the roots to be continuously aeroponically watered on thelower surface of the conveyor belt, while the plant carrier material ishydroponically bathed in the region of the lower deflection points whenthe conveyor belt is in the trough phase.

By fixing the plants on the conveyor belt, the roots are aeroponicallywatered continuously or at least for long periods of time, withoutunnecessarily moistening the leaves of the plant. In this way, diseasesof the leaf mass are reliably prevented. The temperature and humidity ofthe atmosphere below the conveyor belt, in particular along the verticalconveyor path sections, are monitored by a sensor system, and the valuesare suitably controlled by a central control unit such that excessivehumidity can be reliably avoided in said region.

Advantageously, the conveyor path is dimensioned and/or the speed oftravel of the conveyor belt is/are adjusted such that a single up anddown movement of the conveyor belt with one deflection in between, alongwith simultaneous lower-surface moistening of the root region, isconfigured as one module, a cultivation cycle of this kind preferablybeing completed in 24 hours. A modular design advantageously makes itpossible to adapt an overall system for automated plant cultivation toany given requirements, i.e. to any given plant species and/or growingphase. By lengthening the conveyor belt by lining up modules, a completegrowing period for a crop can be easily obtained, each module beingadapted to the needs of the growth stage of the given plants with regardto nutritional requirements, illumination and surface area requirements.For this reason, according to a preferred embodiment of the invention,the individual modules or sections of the conveyor path, together withthe conveyor belt, are designed such that it is possible to change inparticular the length of the lower sections located between twovertically extending path sections. If a plurality of modules isassembled to form an overall system, it makes sense for the distancesbetween an approximately vertically downwardly extending path sectionand an approximately vertically upwardly extending path section to widenas the transport duration of the plants increases, such that thedistances are adapted to the plant growth. By deliberately varying thedistance between the vertically extending paths, it is thus possible toadapt the distance to the given size of the plants fixed on the conveyorbelt.

Furthermore, alternatively or as a complement to the above-describedembodiment, it is advantageously conceivable to achieve the adjustmentof a device for automated plant cultivation to the size requirements ofthe given plants by changing the distance between the points at whichthe individual plants are fixed on the conveyor belt. Preferably,mechanical elements are provided for this purpose, which ensure that thedistance between the individual fixing points can be adjusted asrequired. For instance, it is conceivable for the individual fixingpoints to be spread further apart as the transport duration of a plantincreases and the plant grows, with locking positions in differentpositions being conceivable. According to a further preferred embodimentof the invention, the conveyor belt has stiff lined-up slats, which maybe made of various materials, such as polyvinyl chloride (PVC). Slats ofthis kind allow the plants to be easily anchored and are at the sametime distinguished by a high degree of flexibility such that theconveyor belt can be guided over the deflection pulleys.

By adjusting the conveyor path or the conveyor belt to the changing sizeof the plants in this way, the increasing space requirement of the plantis met, and the use of material and energy is minimized. In this way,the system is operated particularly efficiently from both economical andecological perspectives since expenditure is significantly reduced inthe seedling phase for watering and illumination, for example.

According to the invention, the conveyor path or the conveyor belt movedalong the conveyor path is moved along a closed circular or oval path.Two vertical sections and two horizontal sections in the region of thedeflection points are thus provided, the horizontal sectionsinterconnecting the vertical sections. By changing the length of thevertical sections of the conveyor belt, it is possible to construct aplant cultivation system of this kind to be, at least, practically astall as desired. Preferably, an internal aeroponic nutrient supply forcultivating the moved plants is provided. A plant cultivation system ofthis kind is particularly suitable for cultivating strawberries, leaflettuce, spinach, rocket and/or bush tomatoes. An advantageous harvestis possible if the plants or fruits are harvested in the region of thelower deflection point, in particular by means of an automatedharvesting machine.

According to a further specific embodiment of the device according tothe invention, an illumination unit is provided, which allows the plantsto be irradiated with the suitable wavelengths in a selective,controlled manner. In this case too, it is again conceivable to adaptthe illumination to the given needs of the plant and/or the differentgrowth phases. In this way, the illumination of the plants is speciallyadapted to the plant growth. According to a further embodiment, thedevice is designed such that both illuminated and non-illuminatedsections of the conveyor path are provided.

Furthermore, the device for automated plant cultivation according to theinvention preferably has a fitting system, by means of which theconveyor belt and/or the carrier material provided on the conveyor beltis fitted with at least one seed and/or a seedling in an automatedmanner. It is also conceivable to provide, in a region of the conveyorbelt, a harvesting module allowing the plant that has grown to a desiredextent, in particular the leaves and/or the fruit, to be harvested.Further preferably, the device according to the invention has a section,preferably upstream of the harvesting model, in which the conveyor beltis cleaned and/or sterilized.

Preferably, a device according to the invention is designed such that afitting unit and a harvesting unit are provided, between which acleaning and/or sterilization system, in particular a steam stylizingsystem, is located in the direction of movement of the conveyor beltsuch that the conveyor belt is cleaned and/or sterilized after the grownplants have been harvested and before refitting.

In relation to the fixing of the plants in or on the conveyor belt, itis in principle conceivable for the seeds and/or seedlings to bedirectly or indirectly fixed in or on the conveyor belt by means of acarrier material. According to an alternative embodiment, the conveyorbelt has suitable plant containers that can be fitted with plants andare fastened to the circulating conveyor belt by means of fasteningelements. In this connection, it is conceivable, for instance, for theconveyor belt to comprise at least one conveyor chain into which a hookof the plant container that serves as a fastening element is hooked assoon as a plant is to be transported along the conveyor path.Accordingly, if plant containers that can be connected to the conveyorbelt are used, said containers are preferably detached from the conveyorbelt or conveyor chain for the harvesting process, cleaned after theharvest is complete, and finally supplied back to the fitting system. Atthe start of the conveyor belt or conveyor tracks, corresponding plantcontainers are hooked into said tracks again after being fitted with aseed or seedling.

In addition to a specific device for automated plant cultivation, theinvention further relates to a method for automated cultivation of cropsor ornamental plants.

An essential feature of the method according to the invention is thatthe plants are transported in a manner rigidly fixed on the conveyorbelt and are continuously orbitropically realigned by being at leastpractically vertically transported, at least temporarily, in conjunctionwith deflections at upper and lower deflection points. As a result ofthe plants being fixedly guided, it is furthermore relatively simple toensure continuous aeroponic watering, without the leaves of the plantsbeing unnecessarily moistened. For this reason, diseases of the leafmass can be largely avoided. The way in which the leaves and the rootregion are spatially separated also allows an atmosphere that can bebetter controlled, and excessive humidity can be reliably avoided.

Furthermore, a particular advantage of the invention is that it ispossible to adapt the conveyor path or the conveyor belt to the size ofthe plants. Preferably, this is done by mechanically expanding theconveyor belt in the region of the fixing points and/or expanding thedistances between individual cultivation modules to meet the increasingspace requirement of the growing plants. An illumination and wateringprocedure that is optimized to the altered distances between the plantsallows considerable savings to be made with regard to set-up and energyconsumption. The device according to the invention, in which cultivationmodules having a vertical loop-like design are preferably lined up in amodular fashion, allows plants to be cultivated in a manner that isparticularly flexible, adapted to the planting and the growth stage ofthe plants, and also economical. Furthermore, a combination with anautomated fitting unit and/or harvesting unit at the start and end,respectively, of the conveyor path advantageously allows considerablecost savings to be made.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in more detail,without limiting the general inventive concept, on the basis ofembodiments and with reference to the drawings.

FIG. 1 is a schematic view of a device for automated plant cultivationaccording to the invention.

FIG. 2 is a plan view of a conveyor belt suitable for a device forautomated plant cultivation.

FIG. 3 is a schematic view of a demonstrator of a plant cultivationsystem according to the invention, used for a plant cultivationexperiment.

DETAILED DESCRIPTION

FIG. 1 is a schematic view of a device for automated plant cultivationaccording to the invention. An essential feature of said device is thatthe plants 8 are fixed on the conveyor belt 2 during transport along theconveyor path 1, the roots of the plants 8 being located, at least forthe most part, on the other side of the conveyor belt 2 in relation tothe leaves. The dimensions of the conveyor path 1 and the movement speedof the conveyor belt 2 are selected such that the period of time overwhich the plants 8 are moved along the conveyor path 1, from placing aseed or seedling on the conveyor belt 2 to removal from the conveyorbelt 2, corresponds to a growing phase of the corresponding plant 8.

In relation to the arrangement of the conveyor path 1, it isparticularly important that the plants 8 fixed on the conveyor belt 2are moved both upwardly and downwardly vertically in sections, while theplants are moved at least temporarily horizontally between theindividual vertical path sections 6, in particular in the region of theupper and lower deflection points 4, 5.

At the start of the conveyor path 1, a fitting unit 12 is provided, bymeans of which the receiving elements 3 of the conveyor belt 2 are eachfitted with a seedling 8. The receiving elements 3 according to thedescribed embodiment each have a carrier material 18, preferably rockwool, in which the plant 8, in particular the roots thereof are fixed.An essential feature is that the roots of the plants 8 are located in aregion 19 below the conveyor belt 2, while the leaves extend in a region20 above the conveyor belt 2. The regions 19, 20 in which the roots andthe leaves are respectively located are thus spatially separate from oneanother. Furthermore, while the plants 8 are moved along the verticalsections 6 of the conveyor path 1, the roots are located in a ventilatedspace in which the plants 8 undergo an aeroponic moistening and nutrientsupply process 9 a.

On account of the specific design of the conveyor path 1, the conveyorbelt 2 alternately moves the plants 8 vertically as far as an upperdeflection point 4 and then down again towards a lower deflection point5. As soon as the plants 8 reach the lower end of the vertical path 6,the plants are moved horizontally at least over a short path section 7.During the movement in the region of the lower deflection point 5, thecarrier material, together with the roots of the plant 8 arrangedtherein, is immersed in an immersion bath 9 b such that the plants 8 arehydroponically moistened and supplied with nutrients. Following the atleast momentary horizontal movement, the plants 8 are moved once againover the next two vertical path sections 6 of the conveyor path 1, withthe upper deflection point 4 therebetween. While the plants 8 are beingmoved along said vertical path sections 6, the plant roots once againundergo aeroponic moistening 9 a on the lower surface of the conveyorbelt 2.

A section of the conveyor path 1 consisting of, firstly, two verticalsections 6 in which the plants 8 are moved from bottom to top and thenfrom top to bottom and, secondly, a deflection point 5 arranged betweenthe vertical sections, is referred to as a module or cultivation module.The configuration of the module and the setting of the speed of theconveyor belt 2 are such that the plants 8 cycle through a module ofthis kind within 24 hours. An overall system is in turn composed of thenumber of modules required to achieve a complete growth phase of thegiven plant 8.

Furthermore, the device for automated plant cultivation has anillumination unit 10 designed such that while being moved along theconveyor path 1, the plants 8 are partly illuminated with artificiallygenerated light and partly not illuminated. In the embodiment shown inFIG. 1, the plants 8 are always illuminated when they are being moveddownwards along a vertical path section 6 between the upper deflectionpoint 4 and the lower deflection point 5. However, a shaded phase 11 isprovided when the plants 8 are being moved along a path sectionextending from bottom to top. In this connection, the illumination unit10 is covered such that the plants 8 are not illuminated. In principleit is conceivable to adapt the type, intensity and duration of theillumination to the given type of plant. In each case, the illuminationis controlled or is appropriately adjusted by means of sensors and acontrol unit. In the embodiment shown in FIG. 1, LED panels that arearranged opposite respective downwardly extending vertical path sections6 are provided as illumination units 10.

Moreover, the device for automated plant cultivation shown in FIG. 1 hasan adjustment unit 21 such that the distance between the individualmodules, which each consist of two vertical path sections 6 and an upperdeflection point 4 arranged therebetween, can be adapted to the growthin size of the individual plants 8. As can be clearly seen in FIG. 1,the size of the plants 8 increases while they are being transportedalong the conveyor path 1. To the extent to which the plants 8 grow, thedistance between the individual modules is increased and theillumination is adapted to the change in the light requirement onaccount of the larger amount of greenery of the plants 8. As acomplement to said measures, the conveyor belt 2 is also designed suchthat the distance between the individual receiving elements 3 in whichthe plants are fixed can be changed on the basis of the plant growth. Aspecific embodiment of a conveyor belt 2 that can be adapted to thegrowth in size of the plants will be described in connection with FIG.2.

At the end of the conveyor path 1, an automated harvesting unit 13 isprovided, which removes, from the circulating conveyor belt 2, theplants 8 that have grown to normal size. Directly upstream of theharvesting unit 13, the conveyor belt 2 is deflected once again and thencirculates back to the fitting unit 12. To ensure the required cleaningand sterilization of the conveyor belt 2, along the path between theharvesting unit 13 and the fitting unit 12 the conveyor belt 2 is firstcleaned and then undergoes surface sterilization by means of a steamsterilization system 14. The conveyor belt 2 thus returns to the fittingunit 12 in a fully cleaned and sterilized state, the fitting unitrefitting the individual receiving elements 3 of the conveyor belt 2with carrier material 18, at least provided that said material cannot beused multiple times, and with seeds or seedlings 8.

As shown in FIG. 1, it is advantageous if the individual receivingelements 3 are first fitted with carrier material 18, provided that thematerial cannot be re-used, and with a seed or seedling 8 in the fittingunit 12 or in an upstream process step, such that the already fittedreceiving elements 3 can be placed on and/or fastened to the conveyorbelt 2.

Generally, however, it is also conceivable for the receiving elements 3to be integrated into the conveyor belt 2 or at least rigidly connectedthereto such that the fitting unit 12 merely inserts a seed or aseedling 8 and, if required, fresh carrier material 18 into thereceiving elements 3.

In both cases, it is possible for the receiving elements 3 to alreadyhave carrier material 18 into which seeds or seedlings 8 are inserted bythe fitting unit 12, or for the individual receptacles 3 of the conveyorbelt 2 to be fitted with a seed or a seedling 8 of which the roots arealready in the carrier material 18.

FIG. 2 is a plan view of a portion of a conveyor belt 2 that can beadapted to the growth of the plants 8 while they are being conveyedalong the conveyor path 1. It makes sense to adjust the distance betweenthe individual receiving elements 3, as appropriate; this is because, asthe plants 8 grow, in particular the leafy component increases, in thecase of heads of lettuce for example, and thus the surface arearequirement of the individual plants 8 also grows. For this reason, theindividual receiving elements 3 of the conveyor belt 2 are suitablyspread apart by means of mechanical elements such that the individualplant 8 has more space to grow and is sufficiently illuminated.

The above-described adaptation is achieved substantially by varying thedistance between the receiving elements 3, in each of which a plant 8 orthe roots thereof is/are fixed in the carrier material 18, on the basisof the time that the plants 8 have spent on the conveyor belt 2. Takinginto consideration the extent and speed of the plant growth, thedistances between the individual receptacles are increased while theplants 8 are being transported. In this connection, FIG. 2 shows aportion of a conveyor belt 2, together with plants 8 fixed thereto, intwo different growth stages of the plants 8. While the plants 8 shown tothe left in in FIG. 2 are still at the start of the conveyor path 1 andare relatively small, the plants are about to be harvested in the stateshown to the right in FIG. 2 and have therefore reached a correspondingsize. To take this growth in size into account, the distances betweenindividual receiving elements 3 are considerably larger in the rightside of FIG. 2 than the corresponding distances in the left side of FIG.2.

In the embodiment shown in FIG. 2, the conveyor belt 2 has conveyorchains 15, to which the individual plant receptacles 3 are fastened bymeans of suitable, elastic transport belts 16. The transport belts 16are designed such that both the distance A between the paralleltransport belts 16 and the distance B between the receiving elements 3fastened to a given transport belt 16 can be changed. While a change tothe distance A can be achieved by moving the transport belts 16outwards, the distances B between the individual receptacles 3 arechanged by elastically elongating the transport belts 16 in thelongitudinal direction. Similarly, an increase in the distances to thereceiving elements 3 not directly connected to the transport belts 16 isachieved by providing, between the receiving elements 3, elasticconnection elements 17 that are accordingly elongated when thetransports belts 16 are moved.

The receptacles 3 can be fastened to the transport belts 16 by hookingat least part of the receptacles 3 into the transport belts 16. It isalso conceivable for at least part of the receptacles 3 to be rigidlyconnected to one transport belt 16 each.

As can be seen in FIG. 2, however, not all the receptacles 3 have to bedirectly connected to a transport belt 16 but can also be indirectlyconnected to at least one transport belt 16 via other receptacles 3 bymeans of elastic connections 17. As the transport time of the plants 8increases, the transport belts 16 are moved apart and longitudinallyelongated, for example by coiling the transport belts around drums thatare moved along the conveyor path by means of the transport mechanism,such that the distances between the receptacles 3, together with theplants 8 therein, increase. In this connection, it is also conceivablefor elastically elongatable elements 17 to be provided merely betweenthe individual receiving elements 3 and for merely the outer receptacles3, i.e. the receptacles 3 located at the corner points in FIG. 2, to bepulled outwards. Similarly, the receptacles 3 could be arranged atdifferent positions in an elastic net, or a corresponding elastic netcould form at least part of the conveyor belt 2, it being possible topull the net apart, as required, in particular on the basis of the plantgrowth, in order to change the distances between the receptacles 3, asrequired.

Furthermore, it is conceivable for the individual receptacles 3 not tobe moved as a result of the movement of elastic connection elements 17,but for the individual receptacles 3 to be individually activelymovable. Irrespective of the type of selected mechanism, it is essentialthat the distances between the individual receiving elements is changedboth in the conveying direction and perpendicular thereto in order tomeet the increasing space requirement of the plants.

To check the technical feasibility and to prove the advantages of thesolution according to the invention, a demonstrator shown schematicallyin FIG. 3 was constructed. Said demonstrator has a conveyor path 1having a conveyor belt 2 that circulates in an oval shape and comprisestwo vertical path sections 6 and two horizontal path sections 7, one inthe region of the upper deflection point 4 and another in the region ofthe lower deflection point 5. The horizontal path sections 7 of theconveyor path 1 are relatively short on account of the design of thedemonstrator and are limited to the particular inversion region of theconveyor belt 2.

The conveyor belt 2 has slats made of a plastics material, preferablypolyvinyl chloride (PVC), which are in the form of roller shutterelements and on which the plants 8 are arranged such that the rootsprotrude into a region 19 below the conveyor belt 2, while the leavesand/or fruits protrude into a region 20 above the conveyor belt 2. Anutrient supply unit 9 comprising means for aeroponic nutrient supply 9a is located below the conveyor belt or within the conveyor belt 2circulating in an oval-like manner. In the embodiment shown, theaeroponic nutrient supply unit has three spraying nozzles 24 in the formof non-drip four-jet heads connected to a recirculating water pumpsystem having a nutrient solution tank 25.

The conveyor belt 2 is driven by means of an electric motor 22 that isconnected to the conveyor belt 2 by means of a worm drive 23.

To illuminate the plants, illumination strips having LEDs are providedas illumination units 10 in the region 20 above the conveyor belt and inparallel with the vertical path sections 6. The drive motor 22 and theillumination strips serving as illumination units 10 are connected to acentral control unit 26, which adapts both the illumination and thespeed at which the plants are moved along the conveyor path 1 to therequirements of the given plants being moved. For example, illuminationand dark or shaded phases can be varied in this way. The demonstratorshown in FIG. 3 was installed in a climatic chamber having variableclimate control and was used for growth experiments on various lettucevarieties.

Starting with the demonstrator shown in FIG. 3, it is conceivable to usethe demonstrator or an at least similarly designed device as a basicmodule for a plant cultivation system comprising a plurality of basicmodules of this kind. It is essential here that it is again possible toprovide, depending on the given requirements of a plant, a plantcultivation system which ensures that vertical and horizontal paths 6, 7are arranged according to requirements and thus in an optimized manner.

Using the demonstrator shown in FIG. 3, a specific plant cultivationexperiment was carried out. A professional pelletized lettuce variety(Expertise RZ) from the company Rijkzwaan was used as a seed material.In a first step, said variety was produced in a nutrient solution in a 2cm rock wool block and under 120 μmol/s/m² of LED light (blue/dark red)for 11 days. In the period, the temperature was set to 27° C. with 65%humidity for 18 hours during the day and to 19° C. with 55% humidity for6 hours at night. Accordingly, the illumination was switched on for 18hours and switched off for 8 hours.

The seedlings were transferred to the demonstrator on day 12, saidseedlings simultaneously being transferred in a 10 cm rock wool blockfor the hydroponic NFT cultivation (NFT: nutrient film technique). Theillumination of around 135 μmol/s/m²was achieved by blue and dark-redLED light strips (GreenPower production module from the companyPhilips). A misting system (from the company Netafim) designed for 5 barand with interval sprinkling was used for the aeroponic nutrient supply,with nutrient solution being sprinkled for a period of 5 seconds, andthe sprinkling then being disabled for 4 minutes.

The pH value of the nutrient solution was set to between 5.5 and 6.5 bymeans of diluted 5% nitric acid, and the nutrient content was kept to0.8-1.0 EC (electrical conductivity) by means of liquid fertilizer (fromthe company YARA).

For the entire cultivation phase, the plants underwent 360 degrees ofrotation over the course of 24 hours by the conveyor belt beinggradually moved. After 3 weeks of cultivation, the leaf biomass wasweighed.

The results of the above-described plant cultivation experiment are setout below. After three weeks of cultivation in the demonstrator system,as shown in FIG. 3, a significant (t-test: 0.03) increase in leafbiomass of up to 25% was observed in comparison with standard hydroponicNFT cultivation with LED illumination. Furthermore, on account of thecontinuous orbitropic realignment, round and uniform heads of lettucewere formed. By contrast, the plants that were cultivated statically andhorizontally on a vertical wall were strongly influenced by thegravitational field of the earth, and the heads were misshapen. It wasthus shown that the embodiment according to the invention induces goodplant growth.

One embodiment of the device according to the invention relates to adevice for promoting the growth of plants 8, including a conveyor belt 2which can be moved along a conveyor path 1 and is intended fortransporting, at least in sections, plants 8 which are at leasttemporarily supplied with nutrients by a nutrient supply 9 andirradiated by an illumination unit 10 during movement along the conveyorpath 1, the conveyor path 1 being at least approximately horizontal inat least one first section 7, and being at least approximately verticalin at least one second section 6, wherein the plants 8 are at leasttemporarily fixed relative to the conveyor belt 2 during transport alongthe conveyor path 1 such that at least parts of roots of the plants 8protrude into a region 19 located below a lower surface of the conveyorbelt 2, while at least parts of leaves and/or fruits of the plants 8protrude into a region 20 located above an upper surface of the conveyorbelt which opposes the lower surface, and the nutrient supply 9includes, in the region 19 located below the lower surface of theconveyor belt, a supply unit 9 for aeroponically supplying the plants 8with nutrients, the supply unit 9 misting a nutrient medium and/ordischarging said nutrient medium towards the lower surface of theconveyor belt.

A first development of the aforementioned embodiment of a deviceaccording to the invention is characterized in that the conveyor belt 2includes, at least in regions, a carrier material 18 in which the plants8 are fixed at least temporarily during transport along the conveyorpath 1.

A second development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the development justdescribed, is characterized in that the conveyor path 1 has a lowerdeflection point 5 between two at least approximately vertical sections6.

A third development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that the conveyor path 1 has an upperdeflection point 4 between two at least approximately vertical sections6.

A fourth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that an at least partly automated fittingunit 12 is provided, which fits the conveyor belt 2 with plant seedsand/or seedlings 8.

A fifth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that at least one section 11 that isilluminated by the illumination unit 10 and one section that is notilluminated are arranged along the conveyor path 1.

A sixth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that the conveyor path 1 has two at leastapproximately vertically extending sections 6 and two horizontalsections 7 that each connect the vertical sections 6, at least onesupply unit for aeroponically supplying the plants 8 with nutrientmedium being arranged between the opposite lower surfaces of theconveyor belt 2 moved along the conveyor path 1.

A seventh development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that the conveyor belt 2 has a pluralityof movably interconnected slats.

An eighth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that the nutrient supply 9 has at leastone immersion bath 9 b containing nutrient solution, at least roots ofthe plants 8 being guided through said immersion path at least insections along the conveyor path 1.

A ninth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that at least adjustment unit 21 isprovided to change the distance between a section of the conveyor path 1extending at least approximately vertically from top to bottom and asection of the conveyor path 1 extending at least approximatelyvertically from bottom to top.

A tenth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that a module is formed by a section ofthe conveyor path 1 extending at least approximately vertically frombottom to top and a section of the conveyor path 1 extending at leastapproximately vertically from top to bottom, and a number of modulesrequired to achieve a growing phase of the plant are interconnected byinterface elements, depending on the plant to be grown, in particularthe space necessary for growth of the plant.

According to an eleventh development of the aforementioned embodiment ofa device according to the invention, the tenth development is developedin that at least one illumination unit (10) is integrated into themodule.

According to a twelfth development of the aforementioned embodiment of adevice according to the invention, the tenth or eleventh development isdeveloped in that two modules are connected by an at least approximatelyhorizontally extending section of the conveyor path 1, the length ofsaid section being selected on the basis of the plant to be grown.

According to a thirteenth development of the aforementioned embodimentof a device according to the invention, the tenth, eleventh or twelfthdevelopment is developed in that the device is produced by assembling atleast two pre-grouped modules.

A fourteenth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that an at least partly automatedharvesting unit 13 is provided, which removes plants 8 from the conveyorbelt 2 at least in part.

A fifteenth development of the aforementioned embodiment of a deviceaccording to the invention, having or not having the developments justdescribed, is characterized in that a cleaning and/or sterilization unit14 for cleaning and/or sterilizing the conveyor belt 2 is arranged in aregion of the conveyor path 1 located between a region in which theplants are removed from the conveyor belt 2 at least in part and aregion in which plant seeds and/or seedlings 8 are fixed on the conveyorbelt 2.

A further special embodiment of a device according to the inventionrelates to a device for promoting the growth of plants 8, including aconveyor belt 2 which can be moved along a conveyor path 1 and isintended for transporting, at least in sections, plants 8 which are atleast temporarily supplied with nutrients by a nutrient supply 9 andirradiated by an illumination unit 10 during movement along the conveyorpath 1, the conveyor path 1 being at least approximately horizontal inat least one first section 7, and being at least approximately verticalin at least one second section 6, wherein the plants 8 are at leasttemporarily fixed relative to the conveyor belt 2 during transport alongthe conveyor path 1 such that at least parts of roots of the plants 8protrude into a region 19 located below a lower surface of the conveyorbelt 2, while at least parts of leaves and/or fruits of the plants 8protrude into a region 20 located above an upper surface of the conveyorbelt which opposes the lower surface, a module being formed by a sectionof the conveyor path 1 extending at least approximately vertically frombottom to top and a section of the conveyor path 1 extending at leastapproximately vertically from top to bottom, and a number of modulesrequired to achieve a growing phase of the plant being interconnected byinterface elements, depending on the plant to be grown, in particularthe space necessary for growth of the plant, and at least two modulesbeing connected by an at least approximately horizontally extendingsection of the conveyor path 1.

A further special embodiment of the invention relates to a method forpromoting the growth of plants 8, in which the plants 8 are moved alonga conveyor path 1 by a conveyor belt 2 and are at least temporarilysupplied with nutrients by a nutrient supply 9 and irradiated by anillumination unit 10 during movement along the conveyor path 1, theplants 8 being moved at least approximately horizontally in at least onefirst section 7 of the conveyor path 1 and at least approximatelyvertically in at least one second section 6 of the conveyor path 1,characterized in that the plants 8 are at least temporarily fixedrelative to the conveyor belt 2 during transport along the conveyor path1 such that at least parts of roots of the plants 8 protrude into aregion 19 located below a lower surface of the conveyor belt 2, while atleast parts of leaves and/or fruits of the plants protrude into a region20 located above an upper surface of the conveyor belt 2 which opposesthe lower surface.

In a first method-based development of the above-described specialembodiment of a method according to the invention, while being moved atleast approximately vertically the plants 8 are at least temporarilyaeroponically supplied with water and/or nutrients.

In a second method-based development of the above-described specialembodiment of a method according to the invention, having or not havingthe first method-based development, while being moved at leastapproximately horizontally the plants 8 are at least temporarilyhydroponically supplied with water and/or nutrients.

In a third method-based development of the above-described specialembodiment of a method according to the invention, having or not havingthe first or second method-based development, the entire conveyor path 1is at least temporarily illuminated.

LIST OF REFERENCE NUMERALS

-   1 conveyor path-   2 conveyor belt-   3 receptacle-   4 upper deflection point-   5 lower deflection point-   6 vertical path section-   7 horizontal path section-   8 plant-   9 nutrient supply unit-   9 a aeroponic nutrient supply unit-   9 b hydroponic nutrient supply unit-   10 illumination unit-   11 shaded phase-   12 fitting unit-   13 harvesting unit-   14 cleaning and sterilizing unit-   15 conveyor chain-   16 transport belt-   17 elastic connection elements-   18 carrier material-   19 region below the conveyor belt-   20 region above the conveyor belt-   21 adjustment unit-   22 electric motor-   23 worm drive-   24 spraying nozzle-   25 nutrient medium tank-   26 central control unit

What is claimed is:
 1. A device for promoting the growth of plants,comprising a conveyor belt which can be moved along a conveyor path andis intended for transporting, at least in sections, plants which are atleast temporarily supplied with nutrients by a nutrient supply andirradiated with natural light, and/or light artificially generated by anillumination unit, during movement along the conveyor path, wherein theconveyor path is at least approximately horizontal in at least one firstsection, and being at least approximately vertical in at least onesecond section, further wherein the conveyor belt moved along theconveyor path is moved along a closed circular or oval path such that adeflection occurs in the region of an upper deflection point and in theregion of a lower deflection point (5), which interconnect the verticalsections, the plants being at least temporarily fixed relative to theconveyor belt during transport along the conveyor path such that atleast parts of roots of the plants protrude into a region located belowa lower surface of the conveyor belt, while at least parts of leavesand/or fruits of the plants protrude into a region located above anupper surface of the conveyor belt which opposes the lower surface. 2.The device according to claim 1, wherein the nutrient supply comprises,in the region located below the lower surface of the conveyor belt, asupply unit for aeroponically supplying the plants with nutrients, thesupply unit misting a nutrient medium and/or discharging said nutrientmedium towards the lower surface of the conveyor belt.
 3. The deviceaccording to claim 1, wherein the conveyor belt comprises, at least inregions, a carrier material in which the plants are fixed at leasttemporarily during transport along the conveyor path.
 4. The deviceaccording to claim 1, wherein an at least partly automated fitting unitis provided, which fits the conveyor belt with plant seeds and/orseedlings.
 5. The device according to claim 1, wherein at least onesection is illuminated by the illumination unit and one section that isnot illuminated are arranged along the conveyor path.
 6. The deviceaccording to claim 1, wherein the conveyor belt comprises a plurality ofmovably interconnected slats.
 7. The device according to claim 1,characterized in that the nutrient supply has at least one immersionbath containing nutrient solution, at least roots of the plants beingguided through said immersion path at least in sections along theconveyor path.
 8. The device according to claim 1, wherein an adjustmentunit is provided to change a length of the vertically arranged sections.9. The device according to claim 1, wherein an at least partly automatedharvesting unit is provided, which removes plants from the conveyor beltat least in part.
 10. The device according to claim 1, wherein acleaning and/or sterilization unit for cleaning and/or sterilizing theconveyor belt is arranged in a region of the conveyor path locatedbetween a region in which the plants are removed from the conveyor beltat least in part and a region in which plant seeds and/or seedlings arefixed on the conveyor belt.
 11. The device according to claim 1, whereinthe conveyor belt moved along the conveyor path circulates in an ovalhaving two vertical path sections and, in the region of the upperdeflection point and in the region of the lower deflection point,horizontal path sections, the horizontal path sections beingcomparatively short and being limited to each reversal region of theconveyor belt.
 12. The device according to claim 1, wherein the conveyorbelt moved along the conveyor path is moved on a closed oval track suchthat there are provided two vertical sections and, in the region of bothan upper and lower deflection point horizontal sections thatinterconnect the vertical sections, a height of a plant growing systembeing able to be set at least practically at any height by changing alength of the vertical sections of the conveyor belt.
 13. A method ofpromoting the growth of plants, comprising providing the device of claim1; and fixing plants to the device, wherein the plants are selected fromthe group consisting of strawberries, lettuce, spinach, rocket tomatoes,and bush tomatoes.
 14. A method for promoting the growth of plants, inwhich the plants are moved along a conveyor path by a conveyor belt andare at least temporarily supplied with nutrients by a nutrient supplyand irradiated with natural light, and/or light artificially generatedby an illumination unit, during movement along the conveyor path, theplants being moved at least approximately horizontally in at least onefirst section of the conveyor path and at least approximately verticallyin at least one second section of the conveyor path, wherein theconveyor belt moved along the conveyor path is moved on a closedcircular or oval path and is deflected in in the region of an upperdeflection point and in the region of a lower deflection point, theplants being at least temporarily fixed relative to the conveyor beltduring transport along the conveyor path such that at least parts ofroots of the plants protrude into a region located below a lower surfaceof the conveyor belt, while at least parts of leaves and/or fruits ofthe plants protrude into a region located above an upper surface of theconveyor belt which opposes the lower surface.
 15. The method accordingto claim 14, wherein while being moved at least approximatelyvertically, the plants are at least temporarily aeroponically suppliedwith water and/or nutrients.
 16. The method according to claim 14,wherein the lengths of the vertical sections of the conveyor belt arechanged.
 17. The method according to claim 14, wherein the entireconveyor path is at least temporarily illuminated.
 18. The methodaccording to claim 14, wherein the conveyor belt (2) is moved along theconveyor path in an oval having two vertical path sections and, in theregion of the upper deflection point and in the region of the lowerdeflection point, horizontal path sections, the horizontal path sectionsbeing comparatively short and being limited to each reversal region ofthe conveyor belt.
 19. The method according to claim 14, wherein theconveyor belt is moved along the conveyor path on a closed oval tracksuch that there are provided two vertical sections and, in the region ofboth an upper and lower deflection point, horizontal sections thatinterconnect the vertical sections, a height of a plant growing systembeing able to be set at least practically at any height by changing alength of the vertical sections of the conveyor belt.